This invention relates to a closure device for a bottle of the type having a neck with a mouth and an annular groove below the mouth. Although not restricted thereto, the present invention was developed for use on 18.9 liter (5 U.S. gallon) plastic water bottles. The preferred embodiments also incorporate an integral carrying handle and means to allow the use of a tamper-resistant seal.
With the growing popularity of bottled drinking water, one of the commonest containers has become the ubiquitous 18.9 liter (5 U.S. gallon) plastic bottle used on water dispensers. According to one industry source, there are now some 36 million such bottles in North America, and these bottles are refilled on the average, about 24 times per year. Presently, the bottles are sealed after filling with a non-reusable, heat-shrink plastic cap which is discarded by the end user. This contributes about 3.9 metric tonnes of non-biodegradable solid waste to the North American environment. It is believed that such 18.9 liter plastic bottles constitute a virtual universal design used in many, if not most, countries of the world so that the aforementioned non-reusable caps would constitute, world-wide, a substantial amount of solid waste.
The existing bottles do not permit the use of a threaded closure, reusable or otherwise. Also, it would not be practical to change the design of the bottle to include a threaded mouth, due to the added problem of possible incompatibility with the dispensers, and with the problem of recycling 36 million bottles. Also, the type of moulds and production techniques presently used to manufacture the bottles cannot easily adapt to produce a threaded bottle. Lastly, if a threaded bottle could be used, it would have a shorter life than present bottles due to the added potential of thread damage in use and handling.
Another shortcoming of the existing bottle/closure is the lack of a handle or other means of lifting, carrying or moving bottles, particularly by the consumer. A full bottle weighs over 19 kg. and is an awkward shape, which poses a significant risk factor for back injuries and similar or related strains. Again, there are numerous technical and logistic reasons which tend to work against any large-scale changes in bottle design as a solution to this problem.